Electronic device including a feature in an opening

ABSTRACT

A semiconductor substrate can be patterned to define a trench and a feature. In an embodiment, the trench can be formed such that after filling the trench with a material, a bottom portion of the filled trench may be exposed during a substrate thinning operation. In another embodiment, the trench can be filled with a thermal oxide. The feature can have a shape that reduces the likelihood that a distance between the feature and a wall of the trench will be changed during subsequent processing. A structure can be at least partly formed within the trench, wherein the structure can have a relatively large area by taking advantage of the depth of the trench. The structure can be useful for making electronic components, such as passive components and through-substrate vias. The process sequence to define the trenches and form the structures can be tailored for many different process flows.

RELATED APPLICATION

This application is a divisional of and claims priority under 35 U.S.C.§120 to U.S. patent application Ser. No. 12/871,390 entitled “ElectronicDevice Including a Feature in a Trench” by Parsey et al. filed Aug. 30,2010, which is assigned to the current assignee hereof and incorporatedherein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to electronic devices and processes offorming electronic devices, and more particularly to electronic devicesincluding features within trenches and processes of forming the same.

RELATED ART

Through-wafer vias are typically used to form connections betweendifferent die in a stacked configuration. Such vias can be formed byforming circuitry at one of the major surfaces of a wafer. The wafer isthen thinned by backgrinding or other mechanical operation, and thenvias are formed though all or substantially all of the remainingthickness of the wafer. Each via has a width that is similar to butslightly smaller than the area occupied by a bond pad. As such, thewidths of the vias are 50 microns or larger. The vias consist of bulksilicon, polysilicon, an elemental metal, a metal alloy, a conductivemetal nitride, or a combination thereof and do not include a discreteinternal feature. In other words, the vias are simple miniature wires.The wafer is singulated to form individual die, and the die can then bestacked such that bond pads of one die are electrically connected tobond pads of another die within the stack because of the vias. Thestacked die are attached to a packaging substrate, and the combinationof packaging substrate and stacked die are assembled into a completedintegrated circuit.

FIG. 1 includes an illustration of top view of a structure 12 used in aprior art electronic device. The structure 12 is used for makingelectrical connections with the through-wafer vias in applications suchas imaging sensors and microscale packaging applications. The structure12 is formed by etching a die substrate 10 to form a conductive centerfeature 14 and an annular trench 16 that surrounds the center feature14. The die substrate 12 and the center feature 14 have substantiallythe same composition and crystal orientation. The center feature has atypical width of 100 microns, and the trench has a width of 15 micronsand a depth of up to several hundred microns. A thermal oxidization isperformed to form a liner oxide 18 along the expose sidewalls of thecenter feature 14 and the annular trench 16. A remaining portion of theannular trench 16 is filled with a dielectric material 19.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example and are not limited in theaccompanying figures.

FIG. 1 includes a top view of a structure used in a prior art electronicdevice. (Prior Art).

FIG. 2 includes a top view of a particular feature within a trench inaccordance the concepts as described herein.

FIG. 3 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 4 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 5 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 6 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 7 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 8 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 9 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 10 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 11 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 12 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 13 includes a top view of another particular feature within anothertrench in accordance the concepts as described herein.

FIG. 14 includes a top view of a particular set features within a trenchin accordance the concepts as described herein.

FIG. 15 includes a top view of another particular set features withinanother trench in accordance the concepts as described herein.

FIG. 16 includes a top view of another particular set features withinanother trench in accordance the concepts as described herein.

FIG. 17 includes a top view of another particular set features withinanother trench in accordance the concepts as described herein.

FIG. 18 includes a top view of another particular set features withinanother trench in accordance the concepts as described herein.

FIG. 19 includes a top view of another particular set features withinanother trench in accordance the concepts as described herein.

FIG. 20 includes a top view of another particular set features withinanother trench in accordance the concepts as described herein.

FIG. 21 includes a top view of a coaxial feedthrough that includes thefeature of FIG. 5.

FIG. 22 includes a top view of a triaxial feedthrough that includes thefeature of FIG. 5.

FIG. 23 includes a top view of a particular set features within aparticular set of trenches in accordance the concepts as describedherein.

FIG. 24 includes an illustration of a cross-sectional view of a portionof a workpiece after forming layer over a substrate.

FIG. 25 includes an illustration of a cross-sectional view of theworkpiece of FIG. 24 after etching trenches into the substrate.

FIG. 26 includes an illustration of a cross-sectional view of theworkpiece of FIG. 27 after forming a liner insulating layer and fillingthe remainder of the trenches with a material.

FIG. 27 includes an illustration of a cross-sectional view of theworkpiece of FIG. 26 after forming and patterning an insulating layer.

FIG. 28 includes an illustration of a cross-sectional view of theworkpiece of FIG. 27 after forming interconnects.

FIG. 29 includes an illustration of a cross-sectional view of theworkpiece of FIG. 28 after removing a backside portion of the substrate.

FIG. 30 includes an illustration of a cross-sectional view of theworkpiece of FIG. 29 after forming and patterning an insulating layerand exposing portions of the material within the trenches.

FIG. 31 includes an illustration of a cross-sectional view of theworkpiece of FIG. 30 after forming underbump and bump metallization.

FIG. 32 includes an illustration of a cross-sectional view of a portionof a workpiece in which a capacitor is formed within the trenches andelectrical connections to capacitor electrodes are along the same sideof the substrate.

FIG. 33 includes an illustration of a cross-sectional view of a portionof a workpiece in which a capacitor is within the trenches andelectrical connections to capacitor electrodes are along the oppositesides of the substrate.

FIG. 34 includes an illustration of a cross-sectional view of a portionof a workpiece in which a diode is within the trenches.

FIG. 35 includes an illustration of a top view of a portion of aworkpiece in which different portions of a conductive material withindifferent trenches are electrically connected in a particulararrangement.

Skilled artisans appreciate that elements in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the elements in the figures maybe exaggerated relative to other elements to help to improveunderstanding of embodiments of the invention.

DETAILED DESCRIPTION

The following description in combination with the figures is provided toassist in understanding the teachings disclosed herein. The followingdiscussion will focus on specific implementations and embodiments of theteachings. This focus is provided to assist in describing the teachingsand should not be interpreted as a limitation on the scope orapplicability of the teachings. However, other teachings can certainlybe utilized in this application. While numerical ranges are describedherein to provide a better understanding of particular embodiments,after reading this specification, skilled artisans will appreciate thatvalues outside the numerical ranges may be used without departing fromthe scope of the present invention.

The term “active component” is intended to mean to an electroniccomponent that includes a control electrode, which when properly biasedturns on or turns off the electronic component, such that electricalcurrent between current electrodes of the electronic component flows ordoes not flow. An example of an active component includes a bipolartransistor, a field-effect transistor, a semiconductor-controlledrectifier, a thyristor, or the like.

The term “electrode component” is intended to mean to a component thatis or can readily be made part of a circuit. An example of an electroniccomponent includes an active component, a passive component, aninterconnect, a via, or the like.

The term “metal” or any of its variants when referring to a material isintended to mean to a material, whether or not a molecular compound,that includes an element that is within any of the Groups 1 to 12,within Groups 13 to 16, an element that is along and below a linedefined by atomic numbers 13 (Al), 31 (Ga), 50 (Sn), 51 (Sb), and 84(Po). Metal does not include Si or Ge, by itself. Group numberscorresponding to columns within the Periodic Table of the elements usethe “New Notation” convention as seen in the CRC Handbook of Chemistryand Physics, 81^(st) Edition (2000-2001).

The term “passive component” is intended to mean to an electroniccomponent that significantly affects a voltage or a current when part ofan electronic circuit, wherein such electronic component does not have acontrol electrode. An example of a passive component includes acapacitor, a diode, an inductor, a resistor, or the like. For thepurposes of this specification, interconnects and vias are not passivecomponents.

The term “substantially fills” when referring to a material being formedwithin an opening or a trench, is intended to mean that most of theopening or trench, or most of a remainder of the opening or trench (if aliner, barrier, or other relatively-thin layer has been previouslyformed) is filled by the material. Note that an incidental void may beformed when substantially filling the opening or trench with thematerial. The term “substantially completely fills” is intended to meanthat substantially all of the opening or trench or substantially all ofthe remainder of the opening or trench is filled with the materialwithout a significant number of voids formed within the opening ortrench.

The terms “comprises,” “comprising,” “includes,” “including,” “has,”“having,” or any other variation thereof, are intended to cover anon-exclusive inclusion. For example, a method, article, or apparatusthat comprises a list of features is not necessarily limited only tothose features but may include other features not expressly listed orinherent to such method, article, or apparatus. Further, unlessexpressly stated to the contrary, “or” refers to an inclusive-or and notto an exclusive-or. For example, a condition A or B is satisfied by anyone of the following: A is true (or present) and B is false (or notpresent), A is false (or not present) and B is true (or present), andboth A and B are true (or present).

Also, the use of “a” or “an” is employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read such that the plurals include one or at least one and thesingular also includes the plural, unless it is clear that it is meantotherwise. For example, when a single item is described herein, morethan one item may be used in place of a single item. Similarly, wheremore than one item is described herein, a single item may be substitutedfor that more than one item.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. The materials, methods, andexamples are illustrative only and not intended to be limiting. To theextent not described herein, many details regarding specific materialsand processing acts are conventional and may be found in textbooks andother sources within the semiconductor and electronic arts.

Finely shaped features can be formed within deep trenches wherein thefeatures substantially maintain their shape even when processed wheretrenches surrounding the features are filled with a material. In anembodiment, the feature can have a shape from a top view that includes asegment that significantly increases the mechanical stability of thefeature. In another embodiment, the feature can have a shape from a topview that is an annulus. Both types of features can have significantlyincreased mechanical stability and can allow a trench to be formed to adepth of at least approximately 40 microns or deeper and besubstantially filled with a material while the feature maintainssubstantially the same spacing from sidewalls of a substrate, and ifpresent, other immediately adjacent features. Embodiments describedherein can achieve relatively large dimensions while only occupying arelatively small amount of die substrate area. In the description below,different shapes of features and trenches that form basic buildingblocks will be described. Clearly, many other shapes may be used withoutdeparting from the scope of the appended claims.

FIG. 2 includes an illustration of a top view of a portion of aworkpiece 20 that includes a die substrate 22, a feature 24 having ashape of an I-beam, and a trench 26 between the die substrate 22 and thefeature 24. The feature 24 includes segments 242, 244, and 246. Segments244 and 246 help to increase the mechanical stability of the feature 24as compared to another feature that would only have segment 242. Thelengths of the segments 242, 244, and 246 lie along different lines,wherein the lines corresponding to the lengths of segments 244 and 246are substantially parallel to each other. In another embodiment (notillustrated), the lengths of segments 244 and 246 are not parallel toone another.

The segment 242 has a segment width (“S”) 248. S can be at least aslarge as the resolution limit of a lithography tool used to pattern theworkpiece 20 to form the feature 24. In an embodiment, S is at leastapproximately 0.6 microns, and in another embodiment, S is at leastapproximately 0.8 microns. In theory, there is no known upper limit onthe value for S; however, as S increases, the amount of die substratearea occupied by the feature 24 along a major surface becomes larger. Smay be up to 5 microns, as at greater than five microns, another simplershape, such as a solid circle (see FIG. 1) or other solid planar shapecan be used. Because embodiments described herein can be used todecrease the size of the features while still maintaining acceptablemechanical stability, S can be less than 2.0 microns. In an embodiment,S is no greater than approximately 1.6 microns, and in anotherembodiment, S is no greater than approximately 1.4 microns. In aparticular embodiment, S is in a range of approximately 0.8 toapproximately 1.2 microns. The segments 244 and 246 can have the samewidth or different widths as compared to the segment 242.

The trench 26 has a trench width (“T”) 268. T can be at least as largeas the resolution limit of a lithography tool used to pattern theworkpiece 20 to define the trench 26. Note that the width of the trench26 can vary as a function of depth, as the trench 26 may be narrowernear the bottom of the trench 26 as compared to the top of the trench26. Thus, T is measured in the trench 26 at an elevation closest to themajor surface of the die substrate 22 from which active components areformed. Similar to S, there is no known upper limit on the value for T;however, as T increases, the amount of die substrate area occupied bythe trench 26 along a major surface becomes larger. Further, arelatively wide trench takes a longer deposition and more material tofill. The trenches may or may not be tapered from top to bottom, orbottom to top, or flared in some manner that is advantageous to thedevice configuration or device performance or improves fabrication.Thus, T may be up to 10 microns from a practical standpoint. In anembodiment, T is no greater than approximately 10 microns, and inanother embodiment, T is no greater than approximately 4.0 microns. In aparticular embodiment, T is in a range of approximately 0.8 microns toapproximately 3.0 microns. Distances between each of the sides of thefeature 24 and its closest corresponding side of the trench 26 can beany of the dimensions as described with respect to the dimension T. Thedistances may be the substantially the same or different along differentsides of the feature 24. In the embodiment illustrated in FIG. 2, thetrench 26 has substantially the same width at all locations along themajor surface of the die substrate 22.

FIG. 3 includes an illustration of a top view of a portion of aworkpiece 30 that includes a die substrate 32, a feature 34 having ashape of an I-beam, and a trench 36 between the die substrate 32 and thefeature 34. Similar to the feature 24, the feature 34 includes segments342, 344, and 346. The feature 34 can be useful in forming an isolationstructure within the trench 36. Unlike the feature 24, the feature 34has notches 347 and 349 at opposite ends of the feature 34. From a topview, the notches 347 and 349 help to keep the distances between sidesof the feature 34 more uniform at substantially all points along theperimeter of the feature 34. Thus, the feature 34 to be thermallyoxidized such that complete oxidation along all sides of the feature 34at any particular elevation occurs substantially simultaneously. Comparethe feature 34 to the feature 24; during thermal oxidation of thefeature 24 and at the same elevation, parts of the feature 24corresponding to the intersection of segments 242 and 244 and theintersection of segments 242 and 246 may not be completely oxidized whenthe remainder of the feature 24 is oxidized. Thus, the feature 34 isless likely to leave residual spikes or needles of die substratematerial within an isolation structure. Therefore, the feature 34 can beuseful in forming a very deep isolation structure, and in a particularembodiment, may extend substantially completely through the diesubstrate 32 after a portion of the die substrate 32 has been removed.The configuration also enhances the strength and stability of the viastructure. The values for S and T as previously described for feature 24may be used for the widths of the segments 342, 344, and 346 of thefeature 34, and the width of the trench 36.

T may be expressed as a relation to S. Such a relationship can be usefulwhen forming an isolation structure in which the trench 36 is filledwith a thermal oxide, wherein the thermal oxidation consumessubstantially all of the feature 34 to a depth of tens of microns intothe trench 36. In an embodiment, T is at least approximately 0.9 timesS, and in another embodiment, T is no greater approximately 5.0 times S.In a particular embodiment, T is in a range of approximately 1.0 toapproximately 4.0 times S, and in another particular embodiment, T canbe in a range of approximately 1.3 to approximately 3.0 times S. Forexample, when S is 0.8 microns, T can be in a range of approximately 1.2microns to approximately 2.0 microns; when S is 1.0 microns, T can be ina range of approximately 1.4 microns to approximately 2.4 microns; andwhen S is 1.2 microns, T can be in a range of approximately 1.6 micronsto approximately 2.8 microns. Such ranges are merely exemplary and arenot intended to limit the range of values for T given a particular valueof S.

In a non-limiting embodiment, the feature 34 has an overall length (“L”)382 and an overall width (“W”) as measured at an elevation closest tothe major surface of the die substrate 32. L can be determined as afunction of S and T as previously described. In a particular embodiment,L is within 20% of the sum of 4 times S and 3 times T or (4S+3T), whenexpressed as a formula. In another particular embodiment, L is within10% of (4S+3T), and in a further particular embodiment, L is within 5%of (4S+3T). W can be expressed as a function of L. In an embodiment, Wis at least 0.4 L, and in another embodiment W is at least 0.6 L. In aparticular embodiment, W is in a range of approximately 0.45 L toapproximately 0.55 L.

While the relationships between S and T have been described with respectto the feature 34 and trench 36, any one or more of such relationshipscan be extended to the widths of segments of other features and widthsof other trenches described herein, including feature 24 and trench 26.Similarly, the relationships between L and W with respect to each otherand S and T may also be used for the feature 24 and the trench 26.

FIGS. 4 and 5 illustrate Y-shaped features and corresponding trenches.FIG. 4 includes an illustration of a top view of a portion of aworkpiece 40 that includes a die substrate 42, a feature 44 having aY-shape, and a trench 46 between the die substrate 42 and the feature44. The feature 44 includes segments 442, 444, and 446 each extending ina different directions from the center of the feature 44. The segment442 has a segment width 448 that can have any value as previouslydescribed for dimension S with respect to the feature 24 in FIG. 2. Thesegments 444 and 446 also have segment widths that can have any value aspreviously described for dimension S with respect to the feature 24 inFIG. 2. As between the segments 442, 444, and 446, they can havesubstantially the same or different segment widths as compared to eachother.

The lengths of the segments 442, 444, and 446 have no theoreticallyknown upper limits; however practical concerns, such as the availablearea of the die substrate 42 can provide a practical upper limit. In anembodiment, the lengths of the segments 442, 444, and 446 are no greaterthan 50 microns, and in another embodiment, the lengths are no greaterthan 9 microns. In a further embodiment, the lengths of the segments areat least as long as the narrowest width for the segments 442, 444, and446, and in still a further embodiment, the length of each segment is atleast 2 times the width of the same segment. In a particular embodiment,the lengths of the segments 442, 444, and 446 are in a range ofapproximately 1.2 microns to approximately 4.0 microns. The trenchstructure may be oriented along selected crystal planes of the substrateto control the oxidation or deposition of the various layers comprisingthe via structure, for example, aligning segments along {100} or {110}or { 111 } directions (or other directions in other substratematerials).

The trench 46 is shaped so that the distance between any point along theside of the trench 46 to a corresponding closest point of the feature 44is more uniform as compared to the feature 54 and trench 56 in FIG. 5.The trench 46 has a trench width 468 that can have any value aspreviously described for dimension T with respect to the trench 26 inFIG. 2 or the relationships between T and S as described with respect tothe feature 34 and the trench 36 in FIG. 3.

FIG. 5 includes an illustration of a top view of a portion of aworkpiece 50 that includes a die substrate 52, a feature 54 having aY-shape, and a trench 56 between the die substrate 52 and the feature54. The feature 54 can have any of the attributes as described withrespect to the feature 44 of FIG. 4. In FIG. 5, the trench 56 differsfrom the trench 46 in that sides of the trench 56 closest to the ends ofsegments 542, 544, and 546 are more squared as compared to correspondingregions of the trench 46 in FIG. 4. From a physical design standpoint,the trench 56 of FIG. 5 may allow simpler calculations to be made when acomputer is used to determine the placement of the trench 56 within anintegrated circuit design. Other than the shapes of the corners of thetrench 56, the trench can have any of the attributes as described withrespect to the trench 46 of FIG. 4. After reading this specification,skilled artisans will be able to determine whether the trench 46 of FIG.4 or the trench 56 of FIG. 5 provides a better choice for theirparticular application.

Other shapes for the features can be used that have segments that canhelp to increase mechanical stability in the embodiments as illustratedin FIGS. 6 to 10. FIG. 6 includes an illustration of a top view of aportion of a workpiece 60 that includes a die substrate 62, a feature 64having a shape of a cross, and a trench 66 between the die substrate 62and the feature 64. The feature 64 includes segments 642, 644, 646, and648 each extending in a different directions from the center of thefeature 64. The features may have only two segments. FIG. 7 includes anillustration of a top view of a portion of a workpiece 70 that includesa die substrate 72, a feature 74 having a shape of a cross, and a trench76 between the die substrate 72 and the feature 74. The feature 74includes segments 742 and 744 each extending in a different directionsfrom the center of the feature 74. The segments 742 and 744 havedifferent widths. The features do not need to have segments that haverectilinear shapes. FIG. 8 includes an illustration of a top view of aportion of a workpiece 80 that includes a die substrate 82, a feature84, and a trench 86 between the die substrate 82 and the feature 84. Thefeature 84 includes a curved segment 842 and a rectilinear segment 844.The curved segment 842 can be generally circular (illustrated), oval,oblong, or another curved shape. The rectilinear segment 844 can help toprovide mechanical stability to the curved segment 842, or vice versa.

The features do not need to have segments that intersect one another atan acute angle. FIG. 9 includes an illustration of a top view of aportion of a workpiece 90 that includes a die substrate 92, a feature 94having a V-shape, and a trench 96 between the die substrate 92 and thefeature 94. The feature 94 includes segments 942 and 944 that intersectat an acute angle. The features can be relatively complex. The shape ofthe trench 106 does not have to match the outer perimeter of thefeature. FIG. 10 includes an illustration of a top view of a portion ofa workpiece 100 that includes a die substrate 102, a feature 104, and atrench 106 between the die substrate 102 and the feature 104. Note thatthe trench 106 has an outer perimeter that is a hexagon, and the feature104 does not have an outer perimeter that is complex and not ahexagonal. The hexagonal shape of the outer perimeter of the trench 106may be useful for automated physical design tools. In FIG. 10, thefeature 104 includes vertical segments 1040, 1044, and 1048 andhorizontal segments 1042 and 1046.

The previously described values for dimensions S and T and theirrelationships with respect to FIGS. 2 and 3 can be used for the featuresand trenches in FIGS. 6 to 10. Note that in FIG. 10, the verticalsegment 1044 is spaced apart from vertical segments 1040 and 1048 by thevalue T, as the space between the vertical segments 1040, 1044, and 1048are portions of the trench 106.

Annular features may be used to increase mechanical stability offeatures. FIG. 11 includes an illustration of a top view of a portion ofa workpiece 110 that includes a die substrate 112, a feature 114 havinga circular annulus, a trench 116 between the die substrate 112 and thefeature 114, and a trench 119 defined by the annulus. The annular shapeof the feature 114 allows the feature to have a smaller outer diameteras compared to the diameter of the feature 14 in FIG. 1 while stillmaintaining mechanical stability. For example, the outer diameter of thefeature 114 of FIG. 11 may be approximately 3 microns and still allowthe trenches 116 and 119 to be over 40 microns deep, and in anotherembodiment over 100 microns deep. The feature 14 of FIG. 1 would likelyneed a diameter of at least 30 microns to achieve similar mechanicalstability at a depth of approximately 40 microns.

The shape of the annular feature does not need to be circular. FIG. 12includes an illustration of a top view of a portion of a workpiece 120that includes a die substrate 122, a feature 124 having a square orrectangular annulus, a trench 126 between the die substrate 122 and thefeature 124, and a trench 129 defined by the annulus. In still otherembodiments, other shapes may be used for annular features. FIG. 13includes an illustration of a top view of a portion of a workpiece 130that includes a die substrate 132, a feature 134 having a hexagonalannulus, a trench 136 between the die substrate 132 and the feature 134,and a trench 139 defined by the annulus. In still other embodiments,other shapes may be used for annular features. The previously describedvalues for dimensions S and T and their relationships with respect toFIGS. 2 and 3 can be used for the features and trenches in FIGS. 11 to13.

A variety of different shapes of features and trenches have beendisclosed. After reading this specification, skilled artisans willappreciate that many other shapes for features and trenches can be usedwithout departing from the teachings herein.

FIGS. 14 to 23 illustrate embodiments in which arrays of features can beused based on cells described in the preceding figures. In general, thenumber of trenches corresponds to the number of components or parts of alarger component that will be formed within the die substrate. Similarto the cells previously described, the particular embodiments asillustrated and described herein are merely exemplary and do not limitthe concepts as described herein.

FIGS. 14 and 15 illustrate features having I-beam shapes located withina trench. FIGS. 14 and 15 can have a relatively dense packing offeatures in the trench by staggering the positions of the features alonga row or a column Each of FIGS. 14 and 15 can be used in forming anelectronic component within the trench or an isolation structure thatsubstantially fills the area defined by the trench illustrated. In aparticular embodiment, the isolation structure substantially completelyfills the area defined by the trench illustrated. Features may beselectively connected using conductive interconnections on either thetop surface, bottom surface or both surfaces.

FIG. 14 includes an illustration of a top view of a portion of aworkpiece 140 that includes a die substrate 142, features 141, 143, 145,and 147, and a trench 146 between the die substrate 142 and the features141, 143, 145, and 147 and between the features themselves. Each of thefeatures 141, 143, 145, and 147 are based on the feature 24 in FIG. 2.FIG. 15 includes an illustration of a top view of a portion of aworkpiece 150 that includes a die substrate 152, features 1512, 1532,1552, and 1572, partial features 1514, 1516, 1518, 1534, 1536, 1554,1556, 1574, 1576, and 1578, and a trench 156 between the die substrate152 and the features 151, 153, 155, and 157 and between the featuresthemselves. Each of the features and partial features are based on thefeature 34 in FIG. 3. The physical design of the embodiment in FIG. 15is well suited for forming an isolation structure by thermal oxidation.

FIGS. 16 to 18 illustrate features having Y-shapes located within atrench. FIG. 16 includes an illustration of a top view of a portion of aworkpiece 160 that includes a die substrate 162, features 1641 to 1646,and a trench 166 between the die substrate 162 and the features 1641 to1646 and between the features themselves. Each of the features 1641 to1646 and the trench 166 are based on the feature 54 and trench 56 inFIG. 5. Note that features 1641 to 1646 are oriented in rows andcolumns, wherein the orientation of the features 1641 to 1646 alternatebetween immediately adjacent rows. The physical design of the embodimentin FIG. 16 is well suited for forming an isolation structure by thermaloxidation.

FIG. 17 includes an illustration of a top view of a portion of aworkpiece 170 that includes a die substrate 172, features 1741 to 1746,and a trench 176 between the die substrate 172 and the features 1741 to1746 and between the features themselves. Each of the features 1741 to1746 and the trench 176 are based on the feature 54 and trench 56 inFIG. 5. Note that features 1741 to 1746 are oriented in rows andcolumns, wherein the orientation of the features are such that along acolumn, the centers of the feature lie along a line, and along a row,the centers of the features are staggered.

FIG. 18 includes an illustration of a top view of a portion of aworkpiece 180 that includes a die substrate 182, features, including afeature 1841, and a trench 186 between the die substrate 182 and thefeatures and between the features themselves. Each of the features isbased on the feature 44 and trench 46 in FIG. 4. Note that the featuresare oriented similar to the features in FIG. 16. Note that the overallshape of the trench 186 makes a 90° bend. Such a bend can be used toavoid forming the trench where electronic components have been or willsubsequently be formed. The electronic components can include activecomponents, such as transistors, or passive components, such asresistors, capacitors, diodes, or the like. In another embodiment (notillustrated), the overall shape of the trench can form a differentangle, such as 45°.

Annular features can be used in the arrays. FIG. 19 includes anillustration of a top view of a portion of a workpiece 190 that includesa die substrate 192, features 1941 to 1945 that define annuli 1991 to1995, and a trench 196 between the die substrate 192 and the features1941 to 1945 and between the features themselves. Each of the features1941 to 1945, the trench 196, and annuli 1991 to 1995 are based on thefeature 134, the trench 136, and annulus 139 in FIG. 13. An electroniccomponent can be formed within each of the trench 196 and the annuli1991 to 1995.

Complex features may also be arranged in an array pattern. FIG. 20includes an illustration of a top view of a portion of a workpiece 200that includes a die substrate 202, features 2041 to 2045, and a trench206 between the die substrate 202 and the features 2041 to 2045 andbetween the features themselves. Each of the features 2041 to 2045 andthe trench 206 are based on the feature 104 and the trench 106 in FIG.10.

FIGS. 21 and 22 illustrate physical designs that can be used for n-axialconnectors. FIG. 21 includes an illustration of a top view of a portionof a workpiece 210 that includes a die substrate 212, features 2142 and2144, annulus 219, and a trench 216 between the die substrate 212 andthe feature 2144. The physical design of FIG. 21 can be used for forminga coaxial connector when a conductive material is formed within theannulus 219 and the trench 216. FIG. 22 includes an illustration of atop view of a portion of a workpiece 220 that includes a die substrate222, features 2242, 2244, and 2246, annuli 2292 and 2294, and a trench226 between the die substrate 222 and the feature 2246. The physicaldesign of FIG. 22 can be used for forming a triaxial connector when aconductive material is formed within the annuli 2292 and 2294 and withinthe trench 226. Higher order axial connector may be created by includingmore annular features that would surround the features 2242.

More than one trench can be used. FIG. 23 includes an illustration of atop view of a portion of a workpiece 230 that includes a die substrate232, features 2341 to 2346 and trenches 2361 to 2366 between the diesubstrate 232 and their corresponding features 2341 to 2346. Theorganization of the trench/feature combinations (that is, a combinationof a trench and its corresponding feature) can be in rows and columns Asillustrated, the trench/feature combinations are organized alongstraight rows and staggered or diagonal columns Other organizations canbe used. For example, the organization can include straight columns orinterdigitated columns for increased packing efficiency.

While exemplary physical designs have been illustrated in FIGS. 2 to 23,other physical designs can be used. Many of the aspects of theillustrated trenches and figures can be put into other combinations. Forexample, any of the cells illustrated in FIGS. 6 to 9, 11, and 12 may bemodified, so that a plurality of features are located within a singletrench. In another embodiment, a plurality of trench/featurecombinations, such as any of the features illustrated in FIGS. 3 to 13can be implemented similar to the embodiment of FIG. 23. Many differentorganizations of such trench/feature combinations may be used. In stilla further embodiment, the die substrate may define different trencheswherein the trenches include different numbers of features. In yetanother embodiment, different shapes of features can be used for thesame die substrate, and in a particular embodiment, different shapes offeatures may be located within the same trench.

Many different physical designs of a trench or set of trenches can betailored to a particular application. In an embodiment, a trench or setof trenches can be located over which a bond pad will be formed. Inanother embodiment, a trench or set of trenches may be formed in unusedportions of the die substrate, such as between functional units of theintegrated circuit. For example, the trench or set of trenches may belocated between a high-voltage component and its associated controlcircuitry, between a memory array and a processing unit (e.g., a centralprocessing unit, a graphical processing unit, etc.). In a furtherembodiment, a single trench with a plurality of features may surround aregion including electronic components that are relatively sensitive tosignals or the operation of other electronic components in a differentregion outside the trench. A grounding plane (or other substantiallyconstant voltage structure) or an insulating material may be formedwithin the trench. After reading this specification, skilled artisanswill appreciate that many other physical designs can be tailored toparticular applications.

The different physical designs can allow different electricalconfigurations between electronic components to be made. A single trenchcan be useful for forming an isolation region or a single electroniccomponent. When the single trench includes a plurality of features, thevolume and surface areas within the trench increases. A relatively largevia or a relatively high-capacitance capacitor can be formed in such atrench. A plurality of trenches can be useful for making arrays ofstructures that can allow some or all of the structures to be connectedin series, parallel, or a combination of series and parallel. Such aconfiguration can be particularly well suited for tuning an integratedcircuit for a particular application. In an embodiment, the number ofstructures connected and how they are connected (for example, seriesversus parallel) can affect the number of turns of an inductor, acumulative resistance, a cumulative capacitance, or the like. Forexample, an antenna that is to operate at a particular frequency mayrequire a two-turn inductor, and an antenna that is to operate atanother particular frequency may require a five-turn inductor. Fuse oranti-fuse connectors may be used, and a laser or other localized energysource can be used to blow fuses or to complete the circuit (foranti-fuses). The ability to have different electrical connections (or alack thereof) allows for much greater flexibility to have many potentialcircuit configurations possible. After reading this specification,skilled artisans will be able to determine how to implement a particularphysical design for a particular application.

Attention is directed to a process of forming an electronic device thatincludes trenches and features. FIG. 24 includes an illustration of across-sectional view of a portion of a workpiece 241 that includes a diesubstrate 243. The die substrate 243 can include a monocrystallinesemiconductor wafer, a semiconductor-on-insulator wafer, a flat paneldisplay (e.g., a silicon layer over a glass plate), or another substrateconventionally used to form electronic devices. The portion of the diesubstrate 243 as illustrated in FIG. 24 includes a Group 14 element(e.g., carbon, silicon, germanium, or any combination thereof) thatincludes an n-type or p-type dopant. In another embodiment, the diesubstrate 243 includes a III-V or II-VI semiconductor material.

The die substrate 243 includes major surfaces 2432 and 2434 that areseparated by an initial thickness. Active and other electroniccomponents will be formed within or over the major surface 2432. In aparticular embodiment, no electronic components are formed along themajor surface 2434 because a subsequent backgrind or other operationwill be performed to significantly reduce the thickness of the diesubstrate 243. When the die substrate 243 is in the form of a wafer, theinitial thickness substantially corresponds to the thickness of thewafer before any processing is performed. In an embodiment, thethickness may be no greater than approximately 2000 microns, and inanother embodiment, the thickness may be no greater than approximately900 microns. In a further embodiment, the thickness is at leastapproximately 300 microns, and in another further embodiment, thethickness is at least approximately 400 microns. In a particularembodiment, the thickness is in a range of approximately 600 toapproximately 800 microns.

An insulating layer 2452 and a stopping layer 2454 (e.g., a polish-stoplayer or an etch-stop layer) are sequentially formed over the substrate243 using a thermal growth technique, a deposition technique, or acombination thereof. Each of the pad layer 2452 and the stopping layer2454 can include an oxide, a nitride, an oxynitride, another suitablematerial, or any combination thereof. In an embodiment, the pad layer2452 has a different composition as compared to the stopping layer 2454.In a particular embodiment, the pad layer 2452 includes an oxide, andthe stopping layer 2454 includes a nitride. A mask layer 247 is formedover the stopping layer 2454 and is patterned to define openings 249under which trenches in the substrate 243 will be formed. From a topview (not illustrated), the openings 249 correspond to the shape of thetrenches to be formed, such as the trenches in FIGS. 2 to 23. In anembodiment, the mask layer 247 includes an organic resist material andhas a thickness of at least 0.8 microns. If needed or desired, thethickness of the mask layer 247 can be increased, as trenches that willbe subsequently formed can be significantly deep. For example, the masklayer 247 can be at least approximately 1.2 microns thick or at leastapproximately 1.5 microns thick. Further, the mask layer 247 can includea plurality of films.

An etch operation is performed to pattern the pad layer 2452, stoppinglayer 2454, and substrate 243 to define trenches 252, as illustrated inFIG. 25. Although not illustrated in FIG. 25 to simplify the drawing,the substrate 243 extends to the major surface 2434 as illustrated inFIG. 24. Referring to FIG. 25, the trenches have a depth 254 as measuredfrom the major surface 2432. The depth 254 can be at least approximately40 microns. In an embodiment, the depth 254 can be at leastapproximately 75 microns, and in another embodiment, can be at leastapproximately 110 microns, at least approximately 200 microns, or more.The shapes of the trenches 252 can be a little narrower near the bottomof the trench as compared to a location closer to the major surface2432. Thus, the widths of the features and trenches as previouslydescribed with respect to FIGS. 2 to 23 may be tapered. The bottoms ofthe trenches are generally flat; however the corners between thesidewalls and bottom of each trench may be rounded. The etch isperformed by any number of deep silicon etch tools using an etchprocess, such as a process as described in U.S. Pat. No. 7,285,228,which is incorporated herein by reference in its entirety. The processdisclosed in the patent is a well-known process for high aspect ratiodeep silicon etching that cycles between isotropic surface passivationof the trench walls, reactive ion etch passivation clearing at thetrench bottom, and isotropic silicon etching of the trench bottomopening. In an embodiment, the selectivity of silicon to an organicresist material can be in a range of approximately 80:1 to 100:1. If amask uses a metal that is not significantly etched by fluorine, such asan MN mask, the selectivity can be substantially higher. Vertical ortapered or shaped trenches can be controlled by the etching conditions.After forming the trenches 252, the mask layer 247 is removed.

The portions of the die substrate 243 between the trenches 252correspond to features, such as any of the features previously describedwith respect to FIGS. 2 to 23. At any particular elevation, thecomposition and crystal orientation of the features are substantiallythe same as the die substrate 243. Thus, if the die substrate 243 is asubstantially monocrystalline semiconductor wafer with a (100) crystalplane along the major surface 2432, then the features will also besubstantially monocrystalline semiconductor with uppermost surfacesalong the (100) crystal plane. If the die substrate 243 has asubstantially constant doping profile at different elevations along thedepth 254 of the trenches, the features will likewise have the samedoping profile. If the die substrate 243 is asemiconductor-on-insulating wafer (not illustrated) and the trenches 252extend through the insulating layer, each of the die substrate 243 andthe features will have substantially the same thicknesses of thesemiconductor and insulating layers disposed over a bulk semiconductorsubstrate.

FIG. 26 includes an illustration of a cross-sectional view of theworkpiece 241 after forming an insulating layer 262 and filling thetrenches with a material 264. Note that the shapes of the trenches andfeatures are formed using shapes as described with respect to FIGS. 2 to23, the shape of the features between the trenches are substantially asformed. In other words, the features do not significantly bend, twist,or otherwise move within the trenches as the trenches are filled. Thus,the movement seen with features of the same general size as used in theprior art can be reduced or even substantially eliminated. As a result,smaller dimensions may be used in the structures, leading to a moreefficient use of area.

The insulating layer 262 can be formed to insulate the sidewalls andbottoms of the trenches before forming the material 264. In anembodiment, the insulating layer 262 has a thickness no greater than 90nm, and in another embodiment, has a thickness no greater than 50 nm. Ina further embodiment, the insulating layer 262 has a thickness of atleast 11 nm, and in still a further embodiment, the insulating layer 262has a thickness of at least 20 nm. In a further embodiment, theinsulating layer may not be present. The insulating layer 262 caninclude an oxide, a nitride, or an oxynitride and can be formedthermally or by a deposition. In a particular embodiment, a thermaloxidation is performed to form the insulating layer 262. When thestopping layer 2454 includes a nitride, the stopping layer 2454 can actas an oxidation barrier to reduce the oxidation of the substrate 243along the major surface 2432.

The material 264 can include a single material or a plurality ofmaterials that can be in the form of layer, a plurality of layers, asingle film, or a plurality of films. The material 264 can beconductive, resistive, an insulator, or a combination therefore (forexample, when forming capacitors within the trenches). The actualmaterial, both composition(s) and number of material(s) will depend onthe electronic component being formed. In the particular embodimentillustrated in FIG. 26, through-wafer vias will be formed, andtherefore, the material 262 is conductive. The material 262 includesamorphous silicon, polycrystalline silicon, a metal (an elemental metal,as opposed to a molecular compound), an alloy, a metal nitride, ametal-semiconductor compound, a metal-semiconductor-nitrogen compound,or the like. The composition of the material 262 may depend on when thematerial 262 is formed. Region 266 can be a region where an electroniccomponent, such as an active component (for example, a transistor), apassive component (for example, a resistor, a capacitor, a diode, or thelike), or any combination thereof are at least partly formed within thesubstrate 243. If the material 262 is formed before forming suchelectronic component within the substrate 243, the material 262 may haveto withstand relatively high temperatures, such as greater than 800° C.An exemplary material can include silicon or a refractory metal element.If the material 262 is formed after forming such electronic componentwithin the substrate 243, the material 262 may not need to withstand atemperature greater than 800° C. In a particular embodiment, thematerial 262 is formed just before or as part of the interleveldielectric (ILD)/interconnect sequence, and the material 262 may beexposed to temperatures as high as 500° C. An exemplary material caninclude silicon or a refractory metal element, copper, silver, a noblemetal element, or any combination thereof.

If needed or desired, the insulating layer 262 can be removed from atrench before forming the material 264 to form a body contact, so thatthe substrate 243 can be biased to a voltage that is substantially thesame as the material 264. The material 264 may include an adhesion film,a barrier film, and a conductive-fill film. In a particular embodiment,the adhesion film includes a refractory metal, the barrier layerincludes a refractory metal nitride, and the conductive-fill filmincludes a refractory metal different from the adhesion film. In anotherparticular embodiment, the material 264 includes doped polysilicon.

The material 264 can be formed by depositing the material 264 using achemical vapor deposition, physical vapor deposition, plating, coating,another suitable technique, or any combination thereof. In a particularembodiment, the material 264 is deposited conformally. The thickness ofthe material 264 is sufficient to substantially fill the trenches, andin a particular embodiment, the material 264 substantially completelyfills the trenches. The actual thickness may depend on the width of thetrenches. As the trenches are wider, a thicker deposition of thematerial 264 may be needed. In an embodiment, the thickness will be atleast half of the width, and can be thicker to account for nonuniformityof the widths of the trenches, thickness of the material 264 across thesubstrate 243, or both. In a particular embodiment, the thickness of thematerial 264 may be approximately 0.9 micron when the widths of thetrenches are approximately 1.6 microns. In another particularembodiment, the thickness of the material 264 may be approximately 1.5micron when the widths of the trenches are approximately 2.8 microns.After reading this specification, skilled artisans will appreciate thatmaking the material 264 too thick is safer than making the material 264too thin. However, as the thickness increases, longer deposition times,higher costs for the material 264, and longer and more costly subsequentremoval operations will result. Accordingly, in an embodiment, thethickness of the material 264 is no thicker than approximately threetimes the width of the widest trench, and in another embodiment, thethickness of the material 264 is no thicker than approximately twice thewidth of the widest trench. As deposited, the material 264 will overliethe pad layer 2452 and the stopping layer 2454 (not illustrated).

A removal operation is performed to remove a portion of the material 264that overlies the stopping layer 2454. The removal operation can beperformed using an etching or polishing technique or using a patternedetch process to leave a conductive routing layer over the stopping layer2454 (not illustrated). The tops of the remaining portions of thematerial 264 may lie along substantially the same elevation as theexposed surface of the stopping layer 2454 (illustrated) or recessedbelow that elevation (not illustrated).

An insulating layer 272 is formed along an exposed surface of theworkpiece and patterned to define openings 274 and 276 over the material264, as illustrated in FIG. 27. The trenches include a set of trenchescloser to the left-hand side of the figure (“left set of trenches”) andanother set of trenches closest to the right-hand side of the figure(“right set of trenches”). The opening 274 exposes the material 264within all trenches within the left set of trenches. However, theopening 276 exposes the material 264 within some, but not all, of thetrenches within the right set of trenches. The significance of theopenings 274 and 276 will be described in more detail later in thisspecification. The insulating layer 272 can include a single film or aplurality of films. The insulating layer 272 can include an oxide, anitride, an oxynitride, or any combination thereof.

Interconnects 284 and 286 are formed within the openings 274 and 276,respectively of the insulating layer 272, as illustrated in FIG. 28. Theinterconnect 284 is electrically connected to the material 264 withinall trenches within left set of trenches. However, the interconnect 286is electrically connected to the material 264 within some, but not all,of the trenches within the right set of trenches. In a particularembodiment, the interconnects 284 and 286 make direct contact with theunderlying material 264. The interconnects 284 and 286 can include asingle film or a plurality of films. The interconnects 284 and 286 caninclude any of the materials as described with respect to the material264. The interconnects 284 and 286 may have the same or differentcomposition as compared to the material 264.

The combination of the insulating layer 272 and interconnects 284 and286 may be part of an interlevel dielectric layer (“ILD”)/interconnectlevel used in conjunction with connecting other electronic components(not illustrated) that are formed at least partly within the substrate243 or may be separate from any of the ILD/interconnect levels.

A portion of the substrate 243 is removed to expose portions of theinsulating layer 262, the material 264, or both. In FIG. 29, portions ofthe insulating layer 262 are exposed, and a major surface 2934 isopposite the major surface 2432. The removal can be performed using asingle operation or a plurality of operations. In an embodiment, most ofthe substrate 243 is removed using a relatively faster, nonselectiveremoval technique, such as backgrinding, polishing, or the like. Beforethe insulating layer 262 is exposed, a relatively slower, more selectiveremoval technique is used. In a particular embodiment, a dry etch or wetetch may be performed.

An insulating layer 302 is formed along the major surface 2934 and ispatterned to define openings 304 and 306 within which portions of thematerial 264 is exposed, as illustrated in FIG. 30. Note that the viewof the workpiece in FIG. 30 is inverted from that of FIG. 29 (rotated180°) to simplify understanding. In the embodiment as illustrated, theinsulating layer 302 can be deposited to a thickness such that theprotrusions corresponding to insulating layer 262 and the material 264are covered. The insulating layer 302 can include a single film or aplurality of films and can include an oxide, a nitride, an oxynitride,or any combination thereof. The insulating layer 302 is then patternedto define openings 304 and 306. In an embodiment, the insulating layers262 and 302 have similar or substantially the same etchingcharacteristics, so that the etch chemistry or etch conditions do notneed to be changed when the insulating layer 302 is reached. The etchingcan be performed such that an endpoint is detected when the material 264is reached. A timed etch may be performed after the endpoint is detectedto ensure portions of the material 264 is exposed within the openings304 and 306. In a particular embodiment, the residual thickness of theinsulating layer 262 within the openings can be at least 5 nm and inanother embodiment, at least 11 nm The residual insulating layer 262within the openings can help reduce the likelihood of forming anelectrical short between the material 262 and the substrate 243 when asubsequent conductive material is formed within the openings 304 and306.

Conductive members 314 and 316 are formed over portions of theinsulating layer 302 and within the openings in the insulating layer302, as illustrated in FIG. 31. In the embodiment illustrated, theconductive members 314 and 316 directly contact the exposed material 264within the openings in the insulating layer 302. The conductive member314 is electrically connected to the interconnect 284, and theconductive member 316 is electrically connected to the interconnect 286.Thus, in an embodiment, the material 264 can be in the form ofthrough-substrate vias that can connect an active component, a passivecomponent, or any combination thereof along the major surface 2432 to adifferent component, a different die, a packaging substrate, a printedwiring board, or the like at or closer to the major surface 2934. Thethrough-substrate via can be formed without subjecting the die substrate243 to a drilling or cutting operation after the die substrate 243 hasbeen formed.

The conductive members 314 and 316 can include an underbumpmetallization 3122 and a bump metallization 3124. The underbumpmetallization 3122 can include an adhesion film, a barrier film, anothersuitable film, or any combination thereof. The underbump metallization3122 can include any of the materials as described with respect to thematerial 264. In a particular embodiment, the underbump metallization3122 can include a metal, a metal alloy, a metal nitride, or anycombination thereof, and the bump metallization 3124 can include a metalor a metal alloy that may flow at a temperature no greater thanapproximately 300° C., so that the bump metallization 3124 can reflowand form an electrical connection to a different die, a packagingsubstrate, a printed wiring board, or the like.

The conductive members 314 and 316 can be formed using a depositiontechnique. In an embodiment, a stencil mask (not illustrated) is placedover the substrate 243, wherein the stencil mask has openings whereconductive members, such as the conductive members 314 and 316 are to beformed. The combination of the workpiece and stencil mask is placed intoa deposition tool, and the underbump metallization 3122 and bumpmetallization 3124 can be sequentially deposited to form the conductivemember 314 and 316. The use of the stencil mask may eliminate the needof a separate patterning step when forming the conductive members 314and 316. In the embodiment as illustrated, the conductive members 314and 316 have substantially the same length, and the pattern of theinsulating layer 302 can determine which portions of the material 264are contacted by the conductive members 314 and 316. In this manner, thesame stencil mask may be used for different integrated circuitconfigurations. In another embodiment (not illustrated), the stencilmask can be designed so that the conductive member 316 is tailored moreclosely to the locations where the material 264 is contacted (that is,the conductive member 316 would have a shorter length).

In another embodiment (not illustrated), the insulating layer 302 can bedeposited and not patterned with a masking layer. In this embodiment,the layer 302 would be uniformly etched or polished along the exposedsurface until the material 264 at all 12 locations illustrated in FIGS.30 and 31 would be exposed. The conductive members 314 and 316 would beformed as previously described. However, the conductive member 316 wouldcontact all six of the underlying portions of the material 264. Becausesome of the portions electrically float, contact between the conductivemember 316 and the material 264 would not cause an electrical short.Capacitive coupling to the substrate 243 would be higher because ofcontact to additional portions of the material 264. This process wouldnot require any resist layers to be formed and patterned when processingthe workpiece along the major surface 2934.

In still another embodiment, a lift-off process can be used. Afterforming the workpiece as illustrated in FIG. 30, a patterned resistlayer can be formed such that openings defined by the resist layeroverlie the openings 304 and 306. Underbump metallization can bedeposited over the patterned resist layer and within the openings in thepatterned resist layer and the openings 304 and 306. The patternedresist layer can be removed along with a portion of the underbumpmetallization overlying the patterned resist layer. Portions of theunderbump metallization can remain in the openings 304 and 306. The bumpmetallization can be formed over the underbump metallization. In aparticular embodiment, the bump metallization can be selectively formedover the underbump metallization, such as selective plating.

In a further embodiment, the insulating layer 302 and conductive members314 and 316 can be replaced by ILD/interconnects similar to theinsulating layer 272 and interconnects 284 and 286 along the oppositeside of the workpiece. Other embodiments regarding interconnects, bumps,and other structures can be used.

As illustrated in FIG. 31, the material 264 is used in athrough-substrate via application. In another embodiment, the material264 can be resistive. As illustrated in FIG. 31, the resistance betweenthe interconnect 286 and the conductive member 316 is approximatelythree times higher than the resistance between the interconnect 284 andthe conductive member 314. In a further embodiment, the portions of thematerial 264 can be connected in different ways. For example, theportions of the material 264 can be connected in series rather than inparallel to allow for different values of resistance by using differentconfigurations of connections.

Other electronic components can be formed. FIG. 32 includes anillustration of a cross-sectional view of a portion of a workpiece 320that includes a capacitor. As illustrated, the workpiece 320 includes adie substrate 322 having major surfaces 3232 and 3234. Portions of thesubstrate 322 between the trenches correspond to the features, such asany one or more of the features as previously described. An insulatinglayer 3230 is formed along the major surface 3232, trenches are formedwithin the substrate 322, and an insulating layer 3212 is formed alongsidewalls of the trenches. The trenches are filled with a material, andin this embodiment, a combination of materials. A capacitor electrodelayer 3242, a capacitor dielectric layer 3244, and another capacitorelectrode layer 3246 are sequentially formed to substantially fill thetrenches. The capacitor electrode layer 3246 and the capacitordielectric layer 3244 are patterned to expose the capacitor electrode3242. An ILD layer 3260 is deposited and patterned to define openings,and interconnects 3262 and 3264 are formed within the openings. Theinterconnect 3262 directly contacts the capacitor electrode layer 3242,and the interconnect 3264 directly contacts the capacitor electrodelayer 3246. The substrate 322 is thinned, but in this particularembodiment, not to the bottoms of the trenches. Still, the trenchesextend through most of the substrate 322. The contacts to the capacitorelectrodes are along the same side of the substrate 322.

FIG. 33 includes an illustration of a cross-sectional view of a portionof a workpiece 330 that includes a capacitor. As illustrated, theworkpiece 330 includes a die substrate 332 having major surfaces 3332and 3334. Portions of the substrate 332 between the trenches correspondto the features, such as any one or more of the features as previouslydescribed. An insulating layer 3330 is formed along the major surface3332, trenches are formed within the substrate 332, and an insulatinglayer 3312 is formed along sidewalls of the trenches. The trenches arefilled with a material, and in this embodiment, a combination ofmaterials. A capacitor electrode layer 3342, a capacitor dielectriclayer 3344, and another capacitor electrode layer 3346 are sequentiallyformed to substantially fill the trenches. In this embodiment, narrowertrench openings, if used, will form through substrate vias when filledwith capacitor electrode layer 3342 and wider trench openings will formcapacitors. The capacitor electrode layer 3346 and the capacitordielectric layer 3344 are patterned to expose the capacitor electrode3342. An ILD layer 3360 is deposited and patterned to define an opening,and interconnect 3364 is formed within the opening. The interconnect3364 directly contacts the capacitor electrode layer 3346. The substrate332 is thinned, an insulating layer 3372 is deposited, and portions ofthe insulating layer 3372 and insulating layer 3312 are removed toexpose portions of the capacitor electrode layer 3342 along bottoms ofthe trenches. Metallization 3384 is formed along the side of thesubstrate 332 opposite from the interconnect 3364. The metallization3384 makes direct contact with the capacitor electrode layer 3342. Thecontacts to the capacitor electrode layers are along the opposite sidesof the substrate 332.

In another embodiment, electrical contacts to a capacitor electrodelayer may be made from both the same side and different sides ascompared to the electrical contact to the other capacitor electrodelayer. For example, metallization along one side of the die substratemay be used to supply a substantially constant voltage, such as V_(DD)or V_(SS) to the capacitor electrode and also supply such substantiallyconstant voltage to an active component, such as to a source or drain ofa field-effect transistor, or to a passive component, such as anothercapacitor, a resistor, or a diode, at least partly formed within the diesubstrate.

FIG. 34 includes an illustration of a cross-sectional view of a portionof a workpiece 340 that includes a diode. As illustrated, the workpiece340 includes a die substrate 342 having major surfaces 3432 and 3434.Portions of the substrate 342 between the trenches correspond to thefeatures, such as any one or more of the features as previouslydescribed. An insulating layer 3430 is formed along the major surface3432, trenches are formed within the substrate 342, and an insulatinglayer 3412 is formed along sidewalls of the trenches. The trenches arefilled with a material, and in this embodiment, a combination ofmaterials. A semiconductor layer 3442 having a conductivity type, andanother semiconductor layer 3446 having the opposite conductivity typeare sequentially formed to substantially fill the trenches. In anembodiment, the dopant concentrations of the semiconductor layers 3442and 3446 can be chosen to achieve a desired breakdown voltage. In aparticular embodiment, the diode can be a Zener diode that can be partof an electrostatic discharge or other overvoltage protection circuit toprovide a dissipation current path to reduce the likelihood of damagingmore sensitive electronic components within the integrated circuit. Byusing the depth of the trenches, less surface area of the die substratemay be used for the protection circuitry. An ILD layer 3460 is depositedand patterned to define an opening, and an interconnect 3464 is formedwithin the opening. The interconnect 3464 directly contacts thecapacitor electrode layer 3446. The substrate 342 is thinned, aninsulating layer 3472 is deposited, and portions of the insulating layer3472 and insulating layer 3412 are removed to expose portions of thesemiconductor layer 3442 along bottoms of the trenches. Metallization3482 is formed along the side of the substrate 342 opposite from theinterconnect 3464. The metallization 3384 makes direct contact with thecapacitor electrode layer 3442.

FIG. 35 illustrates an embodiment in which a helical inductor isillustrated. FIG. 35 includes a top view of a workpiece 350 that issimilar to the workpiece 230 in FIG. 23. The embodiment as illustratedin FIG. 35 includes features 3534 that are within trenches filled with aconductive material 3542. Interconnect 3562 is a terminal for theinductor, and interconnects 3564 provide connections between someportions of the conductive material. Because the interconnects 3562 and3564 are visible as illustrated, they are depicted with solid lines.Interconnect 3582 is another terminal for the inductor, andinterconnects 3584 provide connections between other portions of theconductive material. Because the interconnects 3582 and 3584 are alongthe opposite side of the die substrate (not visible as illustrated),they are depicted with dashed lines.

The embodiments described herein are used to illustrate some potentialphysical designs and electronic configurations that can be used.Particular physical designs and electronic configurations selected canbe selected to meet the needs or desires for a particular application.Other passive electronic components and other configurations can be usedwithout departing from the scope of the concepts described herein. In afurther embodiment, the electronic components can be in the form offusible links.

Embodiments as described herein can allow a feature to be formed withimproved mechanical stability. The mechanical stability can bedetermined by comparing the physical layout as designed to the actualphysical structure achieved at a point during fabrication. If the widthof a trench is designed to be substantially uniform along the sides of afeature, and the actual widths in the physical structure aresignificantly different, then the feature may be considered notmechanically stable. Alternatively, the mechanical stability can bedetermined by comparing the dimensions after structure achieved at apoint during fabrication. If the width of a trench is designed to besubstantially uniform along the sides of a feature, and the actualwidths in the actual physical structure are significantly nonuniform,then the feature may be considered mechanically unstable. Alternatively,mechanical stability can be determined by comparing the dimensions ofthe actual physical structure at different points during fabrication. Ifthe width of a trench changes by more than 10% during a deposition orthermal operation, then the feature may be considered mechanicallyunstable. Alternatively, the mechanical stability can be determined ifthe feature becomes twisted, rotated, bent, or otherwise changes shapeduring a subsequent deposition or thermal operation (other a changesolely caused by the oxidation of the feature itself). If the featuresignificantly changes shape, then the feature may be consideredmechanically unstable. Thus, a feature can be considered mechanicallystable if such feature is not mechanically unstable.

The feature can include a segment that significantly increases themechanical stability of the feature within its corresponding trench. Forexample, see FIGS. 2 to 10. Alternatively, the feature can have anannular shape. For example, see FIGS. 11 to 13. For both sets ofembodiments, the shape of the feature and the spacing between thefeature and die substrate can be substantially the same before and afterfilling the trench. Therefore, electronic components can be formed thatare more uniformly shaped, not only locally, but also across the diesubstrate and between different die substrates from different productionlots. Such uniformity allows for better control of electroniccharacteristics in actual products that are closer to electroniccharacteristics as designed.

Embodiments as described herein can take advantage of the verticaldirection (namely depth) to allow electronic components to be formedwith a relatively large surface area without occupying such area along amajor surface of a die substrate. For a capacitor, a relatively largecapacitance can be achieved, and the capacitor may have electricalconnections along a single side or opposite sides of the die substrate.Through-substrate vias can be formed as part of a die fabricationprocess before a substrate is thinned. Thus, through-substrate vias canbe formed without detriments that may occur if through substrate viaswere to be formed after the die substrate is thinned.

Many different configurations can be used so that electronic componentsformed within the trenches can be connected in parallel or series, andsuch configurations may be realized when forming interconnects andmetallization for the integrated circuit. Thus, an integrated circuitthat may be used in a cellular phone may have one set of connections forone particular communication standard (for example, CDMA) and adifferent set of connections for another particular communicationstandard (for example, GSM).

Flexibility exists regarding when trenches are defined, features areformed, and when the trenches are filled, which is referred to as thetrench-and-fill sequence. In an embodiment, the trench-and-fill sequencemay be performed early in the process flow, such as before fieldisolation regions are formed. In another embodiment, the trench-and-fillsequence may be performed after forming field isolation regions andbefore forming any permanent layers or structures over a major surfaceof the substrate, for example, before a gate dielectric or gateelectrode layer is formed over the major surface. In still anotherembodiment, the trench-and-fill sequence may be performed before or aspart of an interconnect level for the integrated circuit. After readingthis specification, skilled artisans will appreciate that thetrench-and-fill sequence can be integrated into a process flow for manydifferent applications.

Many different aspects and embodiments are possible. Some of thoseaspects and embodiments are described below. After reading thisspecification, skilled artisans will appreciate that those aspects andembodiments are only illustrative and do not limit the scope of thepresent invention.

In a first aspect, an electronic device can include a die substratedefining a first trench having a depth that extends substantiallycompletely through the die substrate, and a first feature that isdisposed within the first trench and spaced apart from the diesubstrate, wherein the first feature can extend along at least most ofthe depth of the first trench. From a top view, the first featureincludes a first segment and a second segment that can be substantiallycontiguous with the first segment, and the second segment cansignificantly increase a mechanical stability of the first feature, ascompared to another feature having the first segment without the secondsegment.

In an embodiment of the first aspect, the first feature includes anI-beam. In a particular embodiment, the I-beam has a length that isapproximately 1.5 to 2.5 times its width. In a more particularembodiment, the I-beam includes a pillar having a segment width (S), andthe first trench has a trench width (T), and the length of the I-beam iswithin 20% of a value that is equal to 4S+3T. In another embodiment,from a top view, the first feature has a Y-shape. In a particularembodiment, the first feature further includes a third segment, and thefirst, second, and third segments have substantially a same length andwidth.

In a further embodiment of the first aspect, the first or second segmentof the first feature has segment width (S), the first trench has atrench width (T), and T is in a range of approximately 1.0 toapproximately 5.0 times S. In a particular embodiment, T isapproximately 1.3 to approximately 3.0 times S. In another furtherembodiment, the electronic device further includes a first electronicstructure within the first trench. In a particular embodiment, firstelectronic structure includes a passive component or a via. In otherparticular embodiment, the electronic device further includes a secondfeature and a second electronic structure, wherein the die substratefurther defines a second trench spaced apart from the first trench, thesecond feature is disposed within the second trench and spaced apartfrom the first feature, the second electronic structure electricallyfloats, and the first electronic structure is part of a circuit.

In another embodiment of the first aspect, the electronic device furtherincludes a second feature within the first trench, wherein the secondfeature is substantially equidistant from the first feature and the diesubstrate. In a particular embodiment, the electronic device includes ann-axial feedthrough, wherein n is a whole number that is at least 2, andthe n-axial feedthrough includes the first electronic structure and thesecond electronic structure.

In a second aspect, an electronic device can include a die substratedefining a first trench having a depth that extends substantiallycompletely through the die substrate. The electronic device can alsoinclude a first feature that is disposed within the first trench andspaced apart from the die substrate. The first feature can extend alongat least most of the depth of the first trench. At the same elevation,the first feature and the die substrate can include substantially a samecomposition and crystal orientation. From a top view, the first featurecan have an annular shape. In an embodiment of the second aspect, theelectronic device further includes a layer that substantially fills aninner portion defined by the first feature.

In a third aspect, a process of forming an electronic device can includeforming a masking layer over a first major surface of a die substrate,and etching the die substrate to define a first feature and a firsttrench surrounding the first feature, wherein the first trench has adepth of at least approximately 40 microns. From a top view, the firstfeature can include a first segment and a second segment that issubstantially contiguous with the first segment, wherein the secondsegment can significantly increase a mechanical stability of the firstfeature, as compared to another feature having the first segment withoutthe second segment. The process can also include filling substantiallyall of the first trench with a material.

In an embodiment of the third aspect, the process further includesthermally oxidizing the die substrate and the first feature, and inanother embodiment, the process further includes depositing a dielectricmaterial. In still another embodiment, filling substantially all of thefirst trench includes depositing a first polysilicon or metal-containingmaterial.

In a further embodiment of the third aspect, the process furtherincludes removing a portion of the die substrate along a second majorsurface of the die substrate to expose the material within the trench,wherein the second major surface is opposite the first major surface. Ina particular embodiment, etching the die substrate also defines otherfeatures and other trenches surrounding the other features, wherein theother features are spaced apart from the first feature, and the othertrenches are spaced apart from the first trench, filling substantiallyall of the first trench includes filling substantially all of the othertrenches with the material. The process can further include removing aportion of the material to form electronic structures within the firstand other trenches, and selectively electrically connecting at leastsome of the electronic structures together. In a more particularembodiment, after selectively electrically connecting at least some ofthe electronic structures together, a particular electronic structure ofthe electronic structure electrically floats. In still a furtherembodiment, the depth is at least approximately 50 microns.

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed is not necessarily the order inwhich they are performed.

Certain features that are, for clarity, described herein in the contextof separate embodiments, may also be provided in combination in a singleembodiment. Conversely, various features that are, for brevity,described in the context of a single embodiment, may also be providedseparately or in any subcombination. Further, reference to values statedin ranges includes each and every value within that range.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

The specification and illustrations of the embodiments described hereinare intended to provide a general understanding of the structure of thevarious embodiments. The specification and illustrations are notintended to serve as an exhaustive and comprehensive description of allof the elements and features of apparatus and systems that use thestructures or methods described herein. Separate embodiments may also beprovided in combination in a single embodiment, and conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.Further, reference to values stated in ranges includes each and everyvalue within that range. Many other embodiments may be apparent toskilled artisans only after reading this specification. Otherembodiments may be used and derived from the disclosure, such that astructural substitution, logical substitution, or another change may bemade without departing from the scope of the disclosure. Accordingly,the disclosure is to be regarded as illustrative rather thanrestrictive.

What is claimed is:
 1. An electronic device comprising: a die substratedefining an opening having a depth that extends substantially completelythrough the die substrate; and a feature that is disposed within theopening and spaced apart from the die substrate, wherein: the featureextends along at least most of the depth of the opening; and at a sameelevation, the feature and the die substrate comprise substantially asame composition and crystal orientation.
 2. The electronic device ofclaim 1, wherein from a top view, the feature includes an I-beam or aY-shape.
 3. The electronic device of claim 1, further comprising a viawithin the opening.
 4. The electronic device of claim 1, further apassive component within the opening.
 5. The electronic device of claim1, further comprising an n-axial connector including a conductivematerial that surrounds the feature.
 6. An electronic device comprising:a die substrate defining an opening having a depth that extendssubstantially completely through the die substrate; and a first featurethat is disposed within the opening and spaced apart from the diesubstrate, wherein the first feature includes: a central segment thathas a first end, a second end opposite the first end; a first segmenthaving a first proximal end and a first distal end, wherein: the firstsegment is closer to the first side of the central segment than to thesecond side of the central segment; the first end of the central segmentis closer to the first proximal end than to the first distal end; andthe first distal end is spaced apart from the central segment; and asecond segment having a second proximal end and a second distal end,wherein: the second segment is closer to the second side of the centralsegment than to the first side of the central segment; the second end ofthe central segment is closer to the second proximal end than to thesecond distal end; and the second distal end is spaced apart from thecentral segment.
 7. The electronic device of claim 6, wherein the firstfeature further comprises a first connecting segment disposed betweenthe first segment and the first side of the central segment.
 8. Theelectronic device of claim 7, wherein at a point closest to the firstside of the central segment, the first connecting segment lies betweenand is spaced apart from the first end of the central segment and acenterpoint of the central segment.
 9. The electronic device of claim 7,wherein the first feature further comprises a second connecting segmentdisposed between the second segment and the second side of the centralsegment.
 10. The electronic device of claim 6, wherein each of the firstsegment and the second segment is spaced apart from the central segment.11. The electronic device of claim 6, wherein a length of the centralsegment is longer than each of lengths of the first segment and thesecond segment.
 12. The electronic device of claim 6, wherein a lengthof the central segment is substantially parallel to lengths of the firstsegment and the second segment.
 13. The electronic device of claim 6,further comprising other features within the opening, wherein each ofthe features is spaced apart from the die substrate and other featureswithin the opening.
 14. The electronic device of claim 13, wherein atleast one of the other features is substantially identical to the firstfeature.
 15. The electronic device of claim 6, further comprising a fillmaterial disposed between the first feature and the die substrate. 16.The electronic device of claim 15, wherein the fill material includes aconductive material.
 17. The electronic device of claim 15, wherein thefill material includes an insulating material.
 18. The electronic deviceof claim 6, wherein at a same elevation, the first feature and the diesubstrate comprise substantially a same composition and crystalorientation.
 19. The electronic device of claim 6, further comprising avia within the opening.
 20. The electronic device of claim 6, furthercomprising a passive component within the opening.